The rate of release of nutrients into the atmosphere is regulated by –

1. pH and moisture

2. Temperature

3. Soil

4. All of the above.

How much of the total quantity of global carbon is dissolved in the oceans?

1. 50%

2. 62%

3. 71%

4. 84%

Approximately how much of carbon is fixed in the biosphere through photosynthesis annually.

1. 4 × ${10}^{13}$ kg

2. 5.4 x ${10}^{15}$ kg

3. 6.4 x ${10}^{11}$ kg

4. 13 x ${10}^4$ kg

Where do we find reservoir for sedimentary type nutrient cycling?

1. Land

2. Sea

3. Earth’s crust

4. Atmosphere

Which of the following contribute to the atmospheric CO₂?
1. Producers
2. Herbivores
3. Saprotrophs
4. All of the above

Which of the following reservoir regulates the amount of carbon dioxide in the atmosphere?

1. Ocean

2. Earth’s crust

3. Land

4. Fossil

Where do we find reservoir for gaseous type nutrient cycling?

1. Land

2. Sea

3. Earth’s crust

4. Atmosphere

What per cent of the dry weight of organisms constitutes carbon?

1. 17%

2. 28%

3. 49%

4. 67%

Which is the second abundant matter in the body of an organism?

1. Phosphorous

2. Hydrogen

3. Carbon

4. Calcium